/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#ifndef SKY_ENGINE_PLATFORM_FONTS_FONTDATACACHE_H_
#define SKY_ENGINE_PLATFORM_FONTS_FONTDATACACHE_H_

#include "flutter/sky/engine/platform/fonts/FontCache.h"
#include "flutter/sky/engine/platform/fonts/FontPlatformData.h"
#include "flutter/sky/engine/wtf/HashMap.h"
#include "flutter/sky/engine/wtf/ListHashSet.h"

namespace blink {

class SimpleFontData;

struct FontDataCacheKeyHash {
  static unsigned hash(const FontPlatformData& platformData) {
    return platformData.hash();
  }

  static bool equal(const FontPlatformData& a, const FontPlatformData& b) {
    return a == b;
  }

  static const bool safeToCompareToEmptyOrDeleted = true;
};

struct FontDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformData> {
  static const bool emptyValueIsZero = true;
  static const bool needsDestruction = true;
  static const FontPlatformData& emptyValue() {
    DEFINE_STATIC_LOCAL(FontPlatformData, key, (0.f, false, false));
    return key;
  }
  static void constructDeletedValue(FontPlatformData& slot, bool) {
    new (NotNull, &slot) FontPlatformData(WTF::HashTableDeletedValue);
  }
  static bool isDeletedValue(const FontPlatformData& value) {
    return value.isHashTableDeletedValue();
  }
};

class FontDataCache {
 public:
  PassRefPtr<SimpleFontData> get(const FontPlatformData*,
                                 ShouldRetain = Retain);
  bool contains(const FontPlatformData*) const;
  void release(const SimpleFontData*);

  // This is used by FontVerticalDataCache to mark all items with vertical data
  // that are currently in cache as "in cache", which is later used to sweep the
  // FontVerticalDataCache.
  void markAllVerticalData();

  // Purges items in FontDataCache according to provided severity.
  // Returns true if any removal of cache items actually occurred.
  bool purge(PurgeSeverity);

 private:
  bool purgeLeastRecentlyUsed(int count);

  typedef HashMap<FontPlatformData,
                  pair<RefPtr<SimpleFontData>, unsigned>,
                  FontDataCacheKeyHash,
                  FontDataCacheKeyTraits>
      Cache;
  Cache m_cache;
  ListHashSet<RefPtr<SimpleFontData>> m_inactiveFontData;
};

}  // namespace blink

#endif  // SKY_ENGINE_PLATFORM_FONTS_FONTDATACACHE_H_
